Safety lock for extractor covers



May 1, 1934. J. F. SHEPARD SAFETY LOCK FOR EXTRACTOR COVERS Filed Aug. 11, 1932 O vented or obstructed.

Patented May I, 1934 UNITED STATES PATENT QFFiCE 1,957,297 SAFETY LOOK FOR EXTRACTOR COVERS Application August 11, 1932, Serial No. 628,383

4 Claims.

5 proved cover lock for extractors which is of very simple form and is effective at all times to prevent opening of the cover when the extractor basket is rotating, thereby serving is a guide against accidental injury. A further object is to provide an improved lock of this kind which may be applied to open top extractors and in which all parts of the locking mechanism are internal to the extractor curb when the extractor cover is closed, and in which the parts operate automatically without attention on the part of the operator and can be depended upon under all conditions.

A further object of the invention is to provide an improved lock of this kind in which the locking part is yieldingly held in or is spring pressed into latching position at all times, even when the extractor basket is stationary; which enables the cover to be closed or opened without hindrance whenever the basket is stationary, but which latch becomes a positive lock or stop abutment as soon as the basket rotates to any reasonable degree.

Further objects of the invention are in part obvious and in part will appear more in detail hereinafter.

In the drawing, Fig. 1 represents a central sectional elevation of the upper part of an extractor embodying my invention; Fig. 2 is a -.ilar section, on a larger scale, of the locking parts,

' showing the same in their positions with the basket stationary or at rest; Fig. 3 is a similar View showing the same parts in their positions when the basket is rotating; Fig. i is a similar view, showing the same parts as actuated by the basket during opening or closing movement thereof; Fig. 5 is a sectional plan view on approximately the line 5-5, Fig. 2; and Fig. 6 is a sectional view, corresponding to Fig. 2 and showing a modification.

The invention is applicable for use on or in connection with any kind of centrifugal extractor involving a rotatable basket which is enclosed within a stationary curb and where access to the basket during its rotation is desirably pre- It may be used, for example, on extractors such as are used in sugar refinement or for other like purposes, and has particular aplication in extractors used for laundry work and is so shown for purposes of illus- 'tration but not in any sense of limitation.

Referring to the drawing, the extractor shown comprises a stationary outer curb or casing 1 with a tub opening 2 provided with a movable or removable cover 3 of any suitable form and illustrated as hinged to the curb at 4. Within the curb rotates the usual foraminous or perforated basket 5 having a top opening 6, said basket being carried by the central rotatable shaft 7.

In the arrangement shown, the shaft '7, or a part attached to and rotating therewith, projects upwardly along the central axis of the cavity in the basket to a position fairly close to the inside of the cover 3, as a result of which I take advantage of the closeness to each other of the shaft cover for providing centrifugally actuated locking connections therebetween, such connections being illustrated in Figs. 2 to 6 inelusive.

In the form shown, the shaft 7 or a basket part attached thereto is provided with an upstanding cap 8, the upper portion 9 of which is shown as a solid metal mass cut out or formed to provide a transversely extending slot or cavity 10 in which is pivoted at 11 a latch or locking member 12 having a tongue 13 provided with upper and lower bevelled faces l4, l5 and which tongue, in the stationary position of the parts, projects outwardly from one side of the cylindrical body or extension 9 of the cap. It is normally urged to such position by a light compression spring 16 and the outward movement of said tongue is limited by the engagement of a shoulder or abutment 1'? with the upper wall of the cavity 10.

The tongue 13 cooperates with an annular shoulder or abutment 18 carried by the cover 3. Said cover is shown as having its major portion formed of heavy wire screen or the like with an outer sheet metal rim l9, and being provided at its center with a sheet metal dome 20 and below it with an annulus 21 carrying the ring 18. These parts are welded, brazed, soldered or otherwise secured to the body of the cover and form a housing which encloses the body 9 on the shaft when the extractor cover is closed, as a result of which, when the extractor is in operation with its basket rotating, it presents to the user merely the smooth surface of the curb and covered at its top by a continuous cover held in place by centrifugal action, as will appear.

When the basketis stationary the cover may be readily moved either to fully closed or to open position, because the inner edge of the an nulus 18 is rounded on: and will travel along the inclined surfaces 14 and 15 of the latch and push the same back, as shown in Fig. 4, so that the cover will pass it, all as will be readily un* derstood. H 77 For centrifugal locking purposesd specially form a part of the latch for cooperation with a part which is operated by centrifugal force. In Figs. 2, 3"and 4 of the drawing this part is a ball 22, say a steel ball of suitable weight, which lies upon a surface 23 of the cavity which slopes outwardly and upwardly, or to the right in Fig. 2. This ball, when the parts are at rest, lies in the position shown in Fig. 2 and the outer'part of the latch has a depenchng portion 24 which will move down outside of the ball to permit the cover to be opened and closed, as in Fig. 4. Said depending tongue 24 is provided at its lower end with a substantially horizontal surface 25, beyond which is an outer depending projection 26, the arrangement being such that with the cover closed and'with the basket rotating, as in Fig. 3, the ball 22 will roll outwardly along the inclined surface 23 to a position beneath the surface 25, so that said ball forms a positive abutment which absolutely prevents any tilting motion of the latch to unlocked or cover releasing position. This locking effect persists so longias the basket rotates to any appreciable degree, and not until the basket comes to rest does the ball move inwardly to its former central position and release the latch for retracting motion by the cover. i

Fig. 6 shows a modification in which the same effect is secured by suspending from the outer end of the latch 12a a locking member 2'? having a lateral projection 20a which forms a weight to unbalance member 2'7 so that by gravity it tends to swing over toward the left in Figifi. Said member at its lower end cooperates with the depression 29, above which is a shoulder or abutment surface 30 and beyond the latter a guard wall 31. Fig. 6 shows the parts in full lines in their positions with the basket at rest.

The 1atch 12ct can be retracted or moved to cover release position, as with the form shown in Fig, 2, in which case the depending locking member 2''! moves downwardly, its lower end entering the recess 29. However, when the basket is rotated member 2'? swings outwardly t6 the dotted line position Fig. 6, its outward swing being limited by ,the abutment wall 31 to a position in which its lower end lies over the abutment surface 30, which therefore becomes a positive stop to prevent motion of the latch 12a to cover release position until the basket stops rotating. When "the parts are at rest, or as a condition of no rotation approaches, the weight 28 tends to swing the member 2'? inwardly to the position shown.

It will be understood, of course, that with both arrangments, when the cover is closed and the basket is'rotating, the latch 12 rotates with the basket, so that the tongue 13 rotates rapidly within the housing formed by members 20, 21,

but no matter what is the position of said tongue during rotation of the basket, it always lies above a part of the annulus 18 and therefore prevents opening movement of the cover.

With both forms the locking effect is positive, is accomplished automatically without attention-by the operator, and safeguards the operator against all possible injury. The cover can be readily opened or closed while the basket is stationary, but cannot be opened when the basket is'rotating.

Other advantages of the invention will be apparent to those skilled in the art.

: What I claim is:

1. A centrifugal extractor, comprising an outer casing provided with a rrrovable cover for annular locking abutment near 'its center, a rotatable basket within said casing havinga central shaft,

and a locking member pivotally connected to said shaft and normally spring pressed to a position overlying the cover shoulder, and centrifugally operated means for maintaining the locking member in said position when the basket rotates.

2. A'centrifugal extractor, comprising an outer casing provided with a movable cover having annular locking shoulder near its center;a rotatable basket within said casing provided with a shaft, and a pivoted locking member carried by said shaft and having a tongue adapted to move out over said cover shoulder, yielding means for normally urging said locking member to said position, and a member movably supported by the shaft and actuated by centrifugal force and thereby moved to a position in which movement of the locking member to cover release position is obstructed when the basket is rotating.

3. A centrifugal extractor, comprising an outer casing having a movable cover provided with an annular locking shoulder near its center, a basket and shaft rotating within said casing, a latch pivotally connected to said shaft and spring pressed outwardly to a position interlocking with said shoulder, and a ball carried by said shaft and movable outwardly by centrifugal force to a posi tion which obstructs movement of said latch to cover release position, for preventing opening movement of the'cover when the basket is ro- 7 tating. V s

i 4. A centrifugal extractor, comprising an outer casing having a movable cover provided with an annular locking abutment near its center; a rotatable basket within said casing having a central shaft, a locking member carried by said shaft and normally spring-pressed to a position overlying ,the abutment, centrifugally operated means for maiutaining the locking member in said position when the basket rotates; and coacting cam means on said member and cover adapted to move the member from its position overlying the abutment by movement of the cover when the basket is sta tionary.

JAMES F. SHEPARD. 

